Black tourmaline is a variety of tourmaline, which is a crystalline boron silicate mineral. According to Yulia Van Doren, author of Crystals: The Modern Guide to Crystal Healing and founder of Goldirocksit’s actually the most abundant (and affordable) type of tourmaline, and it’s filled with iron, resulting in its rich, dark color.
And as Ashley Leavyfounder and educational director of the Love and Light School of Crystal Therapy tells mbg, black tourmaline is primarily found in Brazil and China, though it can also be found in Nigeria, Kenya, Madagascar, and more.
“A lot of iron-based minerals have this historical connection — and modern connection — with protection,” Leavy notes, adding that true black tourmaline will always be opaque. “You shouldn’t really be able to see light through it. If you see any light passing through it, it’s probably a dry white tourmaline or a really, really dark green or even a really dark blue tourmaline.”